Map positions of 47 Arabidopsis sequences with sequence similarity to disease resistance genes
Map positions of 47 Arabidopsis sequences with sequence similarity to disease resistance genes
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DOI：
10.1046/j.1365-313x.1997.12051197.x
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发表时间：
1997-11-01
期刊：
影响因子：
7.2
通讯作者：
Somerville, SC
中科院分区：
文献类型：
--
作者：
Botella, MA;Coleman, MJ;Somerville, SC
图的位置已被确定为42个非冗余拟南芥表达序列标签（EST）显示相似的抗病基因（R-EST），并为3个Pto样序列，用简并引物扩增。采用基于PCR的策略，鉴定了含有EST序列的酵母人工染色体（YAC）克隆。由于许多YAC已经被定位，因此R-EST的位置可以从YAC的地图位置推断。利用F-8（Ler × Col-0）重组自交系（RI），将具有不明确图谱位置的R-EST克隆定位为可裂解多态性序列（CAPS）或限制性片段长度多态性（RFLP）标记。除了两种情况外，在所有情况下，R-EST和Pto样序列都映射到单个独特的位置。一个R-EST和一个Pto样序列分别映射到两个位置。因此，在本研究中总共鉴定了47个位点。一些R-EST出现在集群中，表明它们可能是通过基因复制事件产生的。有趣的是，几个R-EST映射到含有遗传定义的抗病基因的区域。因此，这一系列定位的R-EST可能加快抗病基因的分离。由于cDNA测序计划已经鉴定了估计63%的拟南芥基因，因此大量的R-EST（类似于95个）和推断富含亮氨酸重复类的抗病基因可能存在于拟南芥基因组中。
Map positions have been determined for 42 non-redundant Arabidopsis expressed sequence tags (ESTs) showing similarity to disease resistance genes (R-ESTs), and for three Pto-like sequences that were amplified with degenerate primers. Employing a PCR-based strategy, yeast artificial chromosome (YAC) clones containing the EST sequences were identified. Since many YACs have been mapped, the locations of the R-ESTs could be inferred from the map positions of the YACs. R-EST clones that exhibited ambiguous map positions were mapped as either cleavable amplifiable polymorphic sequence (CAPS) or restriction fragment length polymorphism (RFLP) markers using F-8 (Ler x Col-0) recombinant inbred (RI) lines. In all cases but two, the R-ESTs and Pto-like sequences mapped to single, unique locations. One R-EST and one Pto-like sequence each mapped to two locations. Thus, a total of 47 loci were identified in this study. Several R-ESTs occur in clusters suggesting that they may have arisen via gene duplication events. Interestingly, several R-ESTs map to regions containing genetically defined disease resistance genes. Thus, this collection of mapped R-ESTs may expedite the isolation of disease resistance genes. As the cDNA sequencing projects have identified an estimated 63% of Arabidopsis genes, a very large number of R-ESTs (similar to 95), and by inference disease resistance genes of the leucine-rich repeat-class probably occur in the Arabidopsis genome.